Abstarct: Drought is a natural and climate event that can have severe and long-lasting impacts on natural and human systems. Since, the study of climate changes negative effects on drought severity and duration in a region has got significant importance. The purpose of this research is assessment of climate change impacts on drought in Semnan region in future periods. In order to perform this research, 14 GCM models and three greenhouse gases emission (GHG) scenarios (A2, A1B and B1) were selected to generate climate change scenarios baxsed on precipitation and temperature for baxseline (1971 to 2000) and three future (2010-2039, 2040-2069 and 2070-2099) periods. These scenarios were generated using cumulative probability distribution function (CDF) under three risk levels, 0.25, 0.50 and 0.75, for the future periods. Then the drought condition was evaluated by Standardized Precipitation Index (SPI) and Reconnaissance Drought Index (RDI) for different time scales, (1, 3, 6 and 12-months) for baxseline and coming periods The results indicated that mean annual temperature of Semnan region increases about 2.2oC by 2100, and it also showed a decrease in winter precipitation, and increased precipitation in the spring and partially summer. Also analyzing the drought conditions showed that we will have much more extreme drought class, on 3 and 6-months scales, compared to other scales. Increasing of dry periods and reduction of wet periods are predicted by both the SPI and RDI in four timescale 1, 3, 6 and 12-months, in the future second and third periods. And finally, analyzing severity, duration and magnitude of occurrence drought showed that we will have increases in all three specifications in future periods. According to the results, it has been found that climate change has a considerable impact on drought conditions in Semnan region in the future.